Almost all modern carpets have finishes to make cleaning easier and to enhance the appearance of the carpet. These finishes are applied by the manufacturer as a final treatment. They include anti-soiling, gloss (or sheen), stainblocking, anti-static, water and oil repellency. Occasionally one or more of these properties is built into the fiber instead of the finish. The most common example of this is anti-static properties.
These finishing treatments are to create what is known in the trade as "Fourth and Fifth Generation" carpets. In North America there are generally three types of carpet materials: nylon, polyester and polyolefin. There are also varying methods of how finishes are applied to these carpet materials which results in different degrees of fourth and fifth generation carpet properties.
The majority of household carpets have a final treatment that gives some type of water and oil repellency. Almost all have excellent oil repellency which means that oils such as cooking oil and motor oil will remain beaded on the surface of the carpet for easy cleaning. Polyolefin carpets, which make up 10% of the market, have no oil repellency. Household carpets also have widely varying degrees of water repellency. Some carpets will bead water for a few seconds. Other carpets will bead water until it dries. Still other carpets, although claiming to have water repellency, have none. Without water repellency, beverage spills will be immediately absorbed into carpets, making the spills difficult to remove and increasing the likelihood of permanent staining. Cleaning carpets having water and/or oil repellency may destroy the repellency unless special cleaners are used or the carpets are rinsed thoroughly.
An additional carpet finish is "soil resistance" or "anti-resoiling". This property prevents subsequent soils from adhering to carpets as a result of normal use such as foot traffic on carpets, thus making vacuuming more efficient. Carpets vary tremendously in their anti-soiling properties. In addition, cleaning a carpet with poorly formulated carpet cleaning solutions containing sticky materials such as oily materials, sticky detergents and water absorbent materials such as hygroscopic salts can leave a residue that would attract dirt or dust. Thus freshly cleaned carpets often do "get dirty faster" than a new carpet.
A further carpet finish is stainblocking. Most modern carpets are dyed with acid dyes after they are finished. The concentration of the dye determines the intensity of the color. After dyeing there are often dye sites available. This means that common colored beverages such as Kool-Aid.RTM. or fruit juices that contain acid dyes can permanently dye carpets. However, stain blocked carpets are treated with a special clear dye after dyeing that blocks all of the dye sites thus leaving no place for spilled colored beverage dyes to attach to the carpet. These stain blocked carpets will usually leave light colored spots where spilled colored beverages have dried and the light colored spots can be rinsed completely out with water or a well formulated carpet cleaner.
The gloss or sheen of the carpet is often called the "finish". In fact, this is the only portion of the finish that you can see when you purchase a carpet. This gives a carpet the "luster", "delustered" or "shiny" look. The sheen is an integral part of the formulated finish applied by the manufacturer. The final applied finish determines whether a carpet is "delustered" or has a high gloss. Delustering is common these days because dirt is less visible on carpets with this treatment.
All of the above-described finishes are utilized by carpet manufacturers so that even light colored or white carpets maintain their appearance and are easy to keep clean. Generally, the lighter the carpet's color, the more important these finishes are.
Unfortunately, in cleaning these treated carpets, current carpet cleaners undesirably destroy one or more of the aforementioned finishes, unless thoroughly rinsed. Using large amounts of water when rinsing can have deleterious effects on carpeting, as the padding often will become saturated with water which can result in degradation of the padding and/or carpet. Furthermore, if any of the finishes, such as water repellency, is destroyed during cleaning, the carpet will have to be retreated with additional products.
In addition, many compositions create a powdery or off white finish on the carpet such as the textile treatment compositions described in U.S. Pat. No. 4,043,923 to Loudas.
Further, as one of ordinary skill in the art will appreciate, many of the desired attributes of a carpet cleaning product will interfere with each other. For example, water and oil repellency agents tend to deter anti-resoiling and cleaning properties. In addition, good anti-soiling agents tend to deter water and oil repellency. Further, some additives which are desirable in a consumer product such as fragrance, may cause increased resoiling of carpets.
The difficulty of combining all the desired attributes and cleaning while leaving no visible residue is evidenced by some of the current commercially available carpet care products. For example, Woolite.RTM. spray product, from Reckeli & Coleman, has good cleaning properties but exhibits inferior anti-resoil properties, has no stainblocking properties and eliminates the water and oil repellency finishes of carpets unless it is thoroughly rinsed.
Accordingly, it is an object of the present invention to provide an effective carpet cleaning composition which restores the factory finishes to the carpet fibers without saturating the carpet with a rinsing agent.
An additional object of the present invention is to provide an effective carpet cleaning composition which leaves good water repellency and utilizes a reduced amount of fluorinated hydrocarbons.
It is a further object of the present invention to provide an effective carpet cleaning formulation with cleaning and restoring properties having minimal or no interference with each other.
These and other objectives will become apparent to one of ordinary skill in the art from the Specification and claims of the present invention.